The crystal structures and electrochemical studies of three 2,3-naphthalenic Schiff base copper(II) complexes

Three 2,3-naphthalenic Schiff base ligands 3-hydroxy-N-cyclopentyl-2-naphthaldimine (I), 3-hydroxy-N-cycloheptyl-2-naphthaldimine (II), 3-hydroxy-N-cyclooctyl-2-naphthaldimine (III) and their corresponding Cu-11 complexes (1-3) have been prepared and characterized. The crystal and molecular structures of bis-{(cyclopentyl)[(3-oxo-2H-naphth-2-ylidene)methyl]aminato}copper(II) (1), bis-{(cycloheptyl)[(3-oxo-2H-naphth-2-ylidene)methyl]-aminato}copper(II) (2) and bis-{(cyclooctyl)[(3-oxo-2H-naphth-2-ylidene)-methyl]-aminato}copper(II) (3), have been obtained. The X-ray study shows that the geometry around the metal atom is intermediate between square planar and tetrahedral. Additionally, electrochemical studies on the complexes (1)-(3), show a dependence of the Cu-II/Cu-I potentials on the grade of distortion of the structure. (C) 1998 Elsevier Science Ltd. All rights reserved.